You could easily find maps here that work with iGo/Primo (assuming the naviextras.com indicated)at a very reasonable cost. Like $0.00.
However, you would probably have to 'switch' to a fixed version of the navigation software as these maps probably would not work with a standard retail version.
In order to do this, much more would need to be known about the hardware and software you currently have, and when the software version is determined, you should look and post in the appropriate iGo section.